A wide spectrum of accidents and diseases, including carbon monoxide poisoning, arteriosclerosis and cardiac or respiratory arrest is associated with a Parkinsonism-like syndrome of neurological and behavioral deficits and with basal ganglia damage. Each of these conditions is accompanied by periods of cerebral hypoxia, known to produce lesions in the basal ganglia. We have found in rats that electrolytic or biochemically-induced lesions of the dopamine-containing fibers of the nigrostriatal bundle within the basal ganglia produce a pattern of deficits similar in many ways to the effects of hypoxia in rats and to symptomatic Parkinson's Disease in humans. We propose to study the chronic behavioral and neurological effects of hypoxia in rats. We will also examine the effects of hypoxia on the brain catecholamines, norepinephrine and dopamine, using both biochemical and histological techniques. We wish to determine in particular whether hypoxia produces nigrostriatal damage.